In the production of gears, couplings, and the like, it is known to employ cutting tools of the type referred to as rotary ring cutters. Tools of this type comprise stock removing means located on a ring which is secured to a machine spindle, as shown in U.S. Pat. No. 2,129,077 to Wildhaber, or secured to a cutter head as shown by U.S. Pat. No. 2,828,672 to McMullen. The presence of a ring comprising stock removing means eliminates the need to assemble a cutting tool by positioning individual blades in a cutter head and allows for easy exchange of worn or broken blades or grinding surfaces by simply replacing cutter rings.
With cutter rings it is essential that the ring be centered on the cutter head in order to rotate about the cutter axis with little or no run-out in the radial or axial directions. It is especially important that the cutter is adaptable to variations in ring diameter due to, for example, temperature fluctuations, while maintaining the ring in essentially a run-out free condition.
One manner in which a cutter ring is precisely positioned on a cutter head is shown by U.S. Pat. No. 5,197,231 to Pedersen et al. The cutter head includes a wall surface concentric about an axis of rotation and spaced inwardly of the outer edge of the cutter head. The cutter ring is expanded diametrically to bring its outer surface into contact the wall surface of the cutter head and hence center it on the cutter head. The expansion of the cutter ring is accomplished by a circular disc having a tapered outer edge surface which is urged along the tapered inside surface of the cutter ring to expand the ring. A slit may be included in the ring to facilitate expansion thereof.
In another example, U.S. Pat. No. 5,137,402 to Ball et al. provides a cutter head having a centering disc attached thereto as a means to mount a cutter ring. The centering disc includes a tapered outside edge surface which is complementary with a tapered inside surface of the cutter ring. When the cutter ring is placed on the centering disc, the ring centers itself on the tapered edge surface of the centering disc with the location on the edge surface being dependent of the diameter of the ring. Regardless of ring diameter variations, the cutter ring will center itself on the outer edge surface of the centering disc and thus will rotate true about the cutter axis.
In the preferred embodiment of U.S. Pat. No. 5,137,402, the cutter ring is secured to the cutter head via screws extending from the cutter head into the base of the cutter ring. While there are no performance deficiencies associated with this manner of securing the ring, the arrangement does not lend itself well to quick changing since the entire cutter assembly must be removed from a machine tool and then turned upside-down to access the screws for removing the cutter ring.
It is an object of the present invention to provide means for mounting and securing a cutter ring to a cutter head in a manner whereby the cutter is front-loading. That is, the cutter ring may be loaded onto the cutter head without the need to remove the cutter head from a machine tool.